1. Field of the Invention
The present invention relates to a lens array apparatus and a manufacturing method thereof. In particular, the present invention relates to a lens array apparatus including a plurality of lenses arrayed in a predetermined array direction and a manufacturing method thereof. The lens array apparatus is suitable for allowing each lens to emit incoming light towards a predetermined converging point.
2. Description of the Related Art
Conventionally, in the field of optical fiber communication and the like, a lens array is used in which a plurality of lenses are arrayed in a predetermined array direction.
In this type of lens array, for example, a light-emitting device in which a plurality of vertical cavity surface emitting lasers (VCSEL) are arrayed as light-emitting elements is disposed such that each VCSEL faces each lens. As a result, light emitted from each VCSEL enters each lens. Each lens emits the incoming light towards a predetermined converging point.
Then, at the converging point, the light emitted from each lens enters an optical device disposed on a light-emission side the lens array, such as a light-receiving device (for example, a photodetector) including an optical fiber and a plurality of light-receiving elements.    Patent Literature 1: Japanese Patent Laid-open Publication No. 2004-138982
As shown in FIG. 15, in a conventional lens array 1, each VCSEL 2 of the light-emitting device is disposed on a center axis 5 of each lens 3. The light emitted from each lens 3 advances in a direction perpendicular to the array direction (horizontal direction in FIG. 15).
Therefore, when the lens array 1 is made of a material that easily expands due to heat, as a result of heat expansion of the lens array 1 accompanying a change in ambient temperature, as shown in FIG. 15, a position of a converging point P′ of the light emitted from each lens 3 may become significantly displaced in the array direction of the lenses 3 from a design position P.
When the converging point is displaced in the array direction in this way, a problem occurs in the optical device (optical fiber 6 in FIG. 15) on the emission side of the lens array 1 in that the light emitted from the lens array 1 cannot be appropriately received.